Fluoroelastomer-based composite material

Abstract

High modulus asperities are incorporated into a fluoroelastomer matrix to provide a material which, when cured, exhibits high, stable coefficients of friction over a wide temperature range.

That which is claimed is: 
     
       1. As an article of manufacture a friction material formed of an elastomeric matrix comprising from about 20 to about 50% by weight of an elastomeric copolymer of hexafluoropropylene and vinylidene fluoride, and from about 12 to about 40% by weight of carbon black; and said friction material further containing from about 20 to about 60% by weight of glassy or ceramic asperite particles of from about 0.0001 to about 0.005 inch in effective diameter intermixed with and dispersed throughout said friction material in mechanically held nonbonded relation to provide a friction surface of said article of manufacture including the said matrix and said asperite particles. 
     
     
       2. A friction material composition consisting essentially of an elastomeric matrix having from about 20 to about 50% by weight of an elastomeric copolymer of hexafluoropropylene and vinylidene fluoride, and from about 12 to about 40% by weight of carbon black; and said friction material further consisting of from about 20 to abour 60% by weight of glassy or ceramic asperite particles having a minimum size of 0.0001 inch which are dispersed throughout the copolymer matrix in mechanically held nonbonded relation and assuring a relatively high surface concentration of the asperite particles to provide a friction surface material including said matrix and said particles. 
     
     
       3. A friction material composition as in claim 2 wherein said asperite particles are glass fibers of a size from about 0.0001 to about 0.005 inch in diameter and having a length to diameter ratio of from about 3 to 10,000.